Psychophysiological response of military pilots in different combat flight maneuvers in a flight simulator

Psychophysiological and Dual-Task Effects of Biofeedback and Neurofeedback Interventions in Airforce Pilots: A Pilot Study

(1) Background: Neurofeedback (NFB) and biofeedback (BFB) have been shown to reduce stress, enhance physiological self-regulation, improve cognitive performance, and accelerate response times. Stimulating the sensorimotor rhythm (12-15 Hz) is particularly effective in improving working memory and selective attention. However, most studies on air force pilots focus on addressing post-traumatic stress disorder rather than investigating how these interventions might enhance performance and safety during flights, as explored in the present study. (2) Methods: Twelve Spanish Air Force fighter pilot trainees (mean age = 22.83 (0.94) years) participated in the study. Six pilots underwent 24 sessions of combined NFB and BFB training (experimental group), while six served as controls. (3) Results: The experimental group demonstrated improved heart rate variability during baseline, alarm sounds, math tasks, and real flights, which is indicative of greater parasympathetic modulation. A significant decrease in the Theta/SMR ratio was observed in the experimental group during the same conditions, suggesting improved focus, with lower values than the control group. Cognitive performance improved in the experimental group, with higher accuracy and a greater number of completed operations during math tasks. Regarding dual-task performance, the experimental group showed lower reaction time and a better ratio taps/reaction post-intervention. Psychological benefits included reduced cognitive, somatic, and state anxiety levels, along with increased self-confidence. (4) Conclusions: Neurofeedback and biofeedback training, integrated with real flights, simulators, and virtual reality, can enhance physiological regulation, cognitive performance, and emotional resilience, contributing to improved performance and safety in air force pilots.

Heart Rate Variability in Military Pilots During Flight: A Scoping Review

INTRODUCTION

Piloting an aircraft is a complex multitasking activity that involves managing information in a nonautomatic way and generates a high workload (psychological, cognitive, and physical) for the pilot. The excess of these demands can result in decreased performance and may impair flight safety. Heart rate variability (HRV) has been used in recent studies as a method to investigate operator's workload in complex environments. This measure can assess the stress and recovery ability of the autonomic nervous system. However, a better understanding of flight influence on the pilot's autonomic modulation is necessary. Therefore, this scoping review aims to systematically map the studies related to changes in the autonomic modulation in military pilots during flight, in order to characterize their workload at different times and flight profiles.

MATERIALS AND METHODS

A literature search was conducted using MEDLINE (by PubMed), SCOPUS, and LILACS databases. Recent records (2002-2022) that analyzed HRV in military pilots during flight were included. Meanwhile, studies in which piloting activity was not performed were excluded. The study was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline extension for Scoping Reviews and the Updated Methodological Guidance for the Conduct of Scoping Reviews.

RESULTS

A total of 298 records were obtained, of which 19 were included in the scoping review. The studies analyzed flights performed in high- and low-performance aircrafts, helicopters, and flight simulators, using time domain, frequency domain, and nonlinear HRV indices. Real and simulated flights produced significant autonomic changes. Some flights elicited autonomic nervous system responses that persisted up to 5 h after landing. During real flight, the most sensitive indices for identifying variations in pilot workload were root mean square of successive differences between normal heartbeats, standard deviation of interbeat interval of normal sinus beat (SDNN), ratio of low-frequency to high-frequency power, and Poincaré plot standard deviation perpendicular to the line of identity (SD1), whereas the interbeat interval (RR), SDNN, SD1, and Poincaré plot standard deviation along the line of identity (SD2) were the most sensitive indices when comparing segments of simulated flight with different levels of difficulty.

CONCLUSIONS

This scoping review provided insight into the influence of flight on autonomic modulation in military pilots. Some key themes were highlighted: Increased sympathetic activity during flight, sensibility of different domains of HRV to flight demands, and autonomic changes during recovery time. Future research efforts may allow us to enhance the understanding of pilot's workload limits and to elucidate the optimal postflight recovery time.

Using eye tracking to support professional learning in vision-intensive professions: a case of aviation pilots

In an authentic flight simulator, the instructor is traditionally located behind the learner and is thus unable to observe the pilot’s visual attention (i.e. gaze behaviour). The focus of this article is visual attention in relation to pilots’ professional learning in an Airbus A320 Full Flight Simulator. For this purpose, we measured and analysed pilots’ visual scanning behaviour during flight simulation-based training. Eye-tracking data were collected from the participants (N = 15 pilots in training) to objectively and non-intrusively study their visual attention behaviour. First, we derived and compared the visual scanning patterns. The descriptive statistics revealed the pilots’ visual scanning paths and whether they followed the expected flight protocol. Second, we developed a procedure to automate the analysis. Specifically, a Hidden Markov model (HMM) was used to automatically capture the actual phases of pilots’ visual scanning. The advantage of this technique is that it is not bound to manual assessment based on graphs or descriptive data. In addition, different scanning patterns can be revealed in authentic learning situations where gaze behaviour is not known in advance. Our results illustrate that HMM can provide a complementary approach to descriptive statistics. Implications for future research are discussed, including how artificial intelligence in education could benefit from the HMM approach.

Analysis of heart rate variability during emergency flight simulator missions in fighter pilots

INTRODUCTION

Managing emergency situations in different simulated flight segments can entail a workload that could affect the performance of military pilots. The aim was to analyse the modifications in neurovegetative balance (using HR variability, HRV) of professional fighter pilots attending learning/training sessions on emergency situations in a flight simulator.

METHODS

A total of 18 pilots from the Spanish Air and Space Force were included. HRV was recorded simultaneously during diverse simulated emergency situations in three different flight segments: take-off, in-flight and landing.

RESULTS

The comparison between take-off and in-flight revealed a statistically significant increase (p<0.05) in percentage of consecutive RR intervals that differ by more than 50 ms from each other (pNN50), root mean square of the successive differences (rMSSD), standard desviation 1 and 2 (SD1 and SD2), and a statistically significant decrease (p<0.000) in stress score (SS) and in the sympathetic to parasympathetic ratio (S:PS). Between flight and landing, a statistically significant increase (p<0.05) in mean HR, minimum HR, maximum HR, SS and S:PS was shown, while experiencing a significant decrease (p<0.000) in pNN50, rMSSD and SD2. Finally, between take-off and landing, the variables which showed significant changes (p<0.05), with these changes being a significant increase, were mean HR, minimum HR, maximum HR, rMSSD, SD1 and SD2. SS and S:PS ratios showed a statistically significant decrease (p<0.000).

CONCLUSIONS

An emergency situation in a flight simulator manoeuvre produced an anticipatory anxiety response in pilots, demonstrated by low HRV, which increased during the flight segment and decreased during the landing segment of the flight. Trial registration number NCT04487899.

The role of visual conditions and aircraft type on different aspects of pilot workload

OBJECTIVE

The objective of our work was to assess the impact of flight conditions by aircraft type on the workload estimated using NASA-Task Load Index (NASA-TLX).

BACKGROUND

Learning about subjective workload is important for assessing the impact of a pilot's work environment on their performance in the cockpit. This is an important element of flight safety and includes the prevention of aviation accidents.

METHODS

The study included 146 military pilots that fly the following aircrafts: flying fast-jet (21), fixed-wing (24), and rotary-wing (101). The NASA-TLX questionnaire was used to assess workload and pilots were asked to determine the level of workload resulting from flying under the following conditions: daytime flight (VFR), night-vision flight performed under Night Visual Flight Rules (NVFR), and night-vision flight using night-vision goggles (NVGs).

RESULTS

The highest level of workload was consistently attributed to flights performed under NVG conditions. NVFR conditions were rated as the most burdensome, while VFR conditions were rated as the least burdensome. Fast-jet pilots rated their mental performance and effort workload as significantly higher than pilots of other aircrafts.

CONCLUSION

Pilots' perceived workload is influenced by both flight conditions and the type of aircraft they fly. Workload knowledge is important for flight safety and should be taken into account during training and flight-task planning.

APPLICATION

The results of our study can be useful both in flight training and in work on the effectiveness of the human-machine interface. Awareness of one's own limitations due to the work environment can help improve flight safety.

Cerebral oxygenation and perfusion kinetics monitoring of military aircrew at high G using novel fNIRS wearable system

Introduction

Real-time physiological episode (PE) detection and management in aircrew operating high-performance aircraft (HPA) is crucial for the US Military. This paper addresses the unique challenges posed by high acceleration (G-force) in HPA aircrew and explores the potential of a novel wearable functional near-infrared spectroscopy (fNIRS) system, named NIRSense Aerie, to continuously monitor cerebral oxygenation during high G-force exposure.

Methods

The NIRSense Aerie system is a flight-optimized, wearable fNIRS device designed to monitor tissue oxygenation 13-20 mm below the skin's surface. The system includes an optical frontend adhered to the forehead, an electronics module behind the earcup of aircrew helmets, and a custom adhesive for secure attachment. The fNIRS optical layout incorporates near-distance, middle-distance, and far-distance infrared emitters, a photodetector, and an accelerometer for motion measurements. Data processing involves the modified Beer-Lambert law for computing relative chromophore concentration changes. A human evaluation of the NIRSense Aerie was conducted on six subjects exposed to G-forces up to +9 Gz in an Aerospace Environmental Protection Laboratory centrifuge. fNIRS data, pulse oximetry, and electrocardiography (HR) were collected to analyze cerebral and superficial tissue oxygenation kinetics during G-loading and recovery.

Results

The NIRSense Aerie successfully captured cerebral deoxygenation responses during high G-force exposure, demonstrating its potential for continuous monitoring in challenging operational environments. Pulse oximetry was compromised during G-loading, emphasizing the system's advantage in uninterrupted cerebrovascular monitoring. Significant changes in oxygenation metrics were observed across G-loading levels, with distinct responses in Deoxy-Hb and Oxy-Hb concentrations. HR increased during G-loading, reflecting physiological stress and the anti-G straining maneuver.

Discussion

The NIRSense Aerie shows promise for real-time monitoring of aircrew physiological responses during high G-force exposure. Despite challenges, the system provides valuable insights into cerebral oxygenation kinetics. Future developments aim for miniaturization and optimization for enhanced aircrew comfort and wearability. This technology has potential for improving anti-G straining maneuver learning and retention through real-time cerebral oxygenation feedback during centrifuge training.

The Effect of Expertise during Simulated Flight Emergencies on the Autonomic Response and Operative Performance in Military Pilots

Heart rate variability (HRV) and performance response during emergency flight maneuvers were analyzed. Two expert pilots (ages 35 and 33) and two rookie pilots (ages 25) from the Portuguese Air Force participated in this case-control report study. Participants had to complete the following emergency protocols in a flight simulator: (1) take-off engine failure, (2) flight engine failure close to the base, (3) flight engine failure far away from the base, and (4) alternator failure. The HRV was collected during all these maneuvers, as well as the performance data (the time it took to go through the emergency protocol and the subjective information from the flight simulator operator). Results regarding autonomic modulation showed a higher sympathetic response during the emergency maneuvers when compared to baseline. In some cases, there was also a higher sympathetic response during the emergency maneuvers when compared with the take-off protocol. Regarding performance data, the expert pilots accomplished the missions in less time than the rookie pilots. Autonomic modulation measured from HRV through portable devices can easily relay important information. This information is relevant since characterizing these maneuvers can provide helpful information to design training strategies to improve those psychophysiological responses.

Transcranial Electrical Stimulation Offers the Possibility of Improving Teamwork Among Military Pilots: A Review

Effective teamwork among military pilots is key to successful mission completion. The underlying neural mechanism of teamwork is thought to be inter-brain synchronization (IBS). IBS could also be explained as an incidental phenomenon of cooperative behavior, but the causality between IBS and cooperative behavior could be clarified by directly producing IBS through extra external stimuli applied to functional brain regions. As a non-invasive technology for altering brain function, transcranial electrical stimulation might have the potential to explore whether top-down enhancement of the synchronization of multiple brains can change cooperative behavioral performance among members of a team. This review focuses on the characteristic features of teamwork among military pilots and variations in neuroimaging obtained by hyper-scanning. Furthermore, we discuss the possibility that transcranial electrical stimulation could be used to improve teamwork among military pilots, try to provide a feasible design for doing so, and emphasize crucial aspects to be addressed by future research.

How to play under pressure: EEG monitoring of mental activation training in a professional tennis player

The aim of this study was to monitor the mental activation training during match pressure imageries using a protocol with (MT) and without mental training (wMT) performed in the office and on the tennis court based on the analysis of heart rate, brain waves and subjective ratings in a professional tennis player with high imagery experience. Results showed that both in the office (MTo/wMTo) and on the court (MTc/wMTc) the tennis player's heart rate increased in the match pressure imagery (I.3-8), being higher in the MTo. It decreased in the pressure imagery using mental tools (I.8-13) in the MT. In the case of brainwaves, beta and gamma waves increased in the match pressure imagery (I.3-8); while beta, gamma, delta and theta waves decreased in the pressure imagery using mental tools (I.8-13), being higher in the office. Entropy decreased in the match pressure imagery (I.3-8), being higher in the MTo. It increased in the pressure imagery using mental tools (I.8-13), being higher in the MTo. Regarding subjective ratings, the tennis player felt the pressure in the match pressure imagery, being higher in MT. In the pressure imagery using mental tools he regulated the activation to feel it at an optimal level (7). In the imagery reality, the olfactory and gustatory dimensions were the most difficult to feel in both imageries.

The effect of mental schema evolution on mental workload measurement: an EEG study with simulated quadrotor UAV operation

OBJECTIVE

Mental workload is the result of the interactions between the demands of an operation task and the skills, behavior and perception of the performer. Working under a high mental workload can significantly affect an operator's ability to choose optimal decisions. However, the effect of mental schema, which reflects the level of expertise of an operator, on mental workload remains unclear. Here, we propose a theoretical framework for describing how the evolution of mental schema affects mental workload from the perspective of cognitive processing.

APPROACH

we recruited 51 students to participate in a 10-day simulated UAV flight training. The EEG PSD metrics were used to investigate the changes in neural responses caused by variations in the mental workload at different stages of mental schema evolution.

MAIN RESULTS

It was found that mental schema evolution influenced the direction and change trends of the frontal theta PSD, parietal alpha PSD, and central beta PSD. Initially, before the mental schema was formed, only the frontal theta PSD increased with increasing task difficulty; when the mental schema was initially being developed, the frontal theta PSD and the parietal alpha PSD decreased with increasing task difficulty, while the central beta PSD increased with increasing task difficulty. Finally, as the mental schema gradually matured, the trend of the three indicators did not change with increasing task difficulty. However, differences in the frontal PSD became more pronounced across task difficulty levels, while differences in the parietal PSD narrowed.

SIGNIFICANCE

Our results describe the relationship between the EEG power spectrum and the mental workload of UAV operators as the mental schema evolved. This suggests that EEG indicators can not only provide more accurate measurements of mental workload but also provide insights into the development of an operator's skill level.

Body Composition Symmetry in Aircraft Pilots

The purpose of this study was to analyze the body composition symmetry in upper and lower body segments of aircrafts pilots. To reach the study aim, body composition in upper and lower body segments of 206 male aircraft pilots of the Spanish Army (23.1 ± 6.87 years) and 105 civilians (24.0 ± 6.29 years) were evaluated by a bioimpedance analyser (InBody 720, Biospace Co. Ltd., Seoul, Korea). Aircraft pilots presented a tendency to dysmetria in upper and lower body segments, showing fitter values in the protagonist side when performing flight functions. Dysmetria could be detrimental during flight manoeuvres and produce injuries in aircraft pilots. It would be recommended to design specific training protocols to improve this imbalance.

A Digital Twin-Based Platform towards Intelligent Automation with Virtual Counterparts of Flight and Air Traffic Control Operations

Automation technologies have been deployed widely to boost the efficiency of production and operations, to trim the complicated process, and to reduce the human error involved. Nevertheless, aviation remains human-centred and requires collaboration between different parties. Given the lack of a collaborative decision-making training platform for air traffic operations in the industry, this study utilises the concept of cyber-physical systems (CPS) to formulate a system architecture for pilots and air traffic control officers training in collaborative decision making by linking and integrating the virtual counterparts of flights and air traffic control operations. Collaborative decision-making training and the corresponding intelligent automation aids could be realised and supported. A performance analysis via a flight task undertaken with different computational load settings was prepared to evaluate the platform’s latency and integrity. The latency is presented using its 95% confidence interval, and integrity is presented using the percentage of data loss during wireless transmission. The results demonstrated convincing performance and a promising system robustness in both domains.